Summary
Even though this section of the web resource in not very large, it highlights some important issues related to the use, or lack of use, of instructional audio. At the time of writing, the author referred to audio as the “forgotten medium”, and commented on the peculiar fact of the general neglect of audio as an instructional medium. This peculiarity is highlighted both by the pervasive commercial use of audio as a communication medium for over a half century, and audio’s power and range (e.g. simple messages to complex dramas). The two characteristics of audio that may make it unsuitable for come instructional contexts are its linearity, and slower transmission rate (compared to text).

All communication mediums have specific strengths and weaknesses, which must be taken into consideration when selecting a medium for instructional messages. The article identifies several reasons for considering the use of instructional audio. These are:
• Overcoming listener limitations (e.g. visual impairment)
• Situating content (use of environmental sounds to enable mental visualization)
• Providing a common experience (everyone receives the exact same message)
• Producing a change in affect (feelings)
• Hearing it as it happens (capture real-time events. E.g. Flight 93, on 9/11)

Commentary
The vast majority of the literature I have reviewed to date deals with instructional audio as a medium for teaching and learning procedural content. To be sure, research like Moreno & Mayer (1999, 2000), Mayer, Subko & Mautone (2003), and Mayer, Moreno, et al, (1999), represent some of the best research in the effective use of instructional audio. However, their body of research has been criticized for using procedural content to the exclusion of conceptual content (Tabbers, Martens, & van Merriëboer, 2004). Interestingly, this article is the first I have read that focuses more on instructional audio’s potential for producing affective learning outcomes, than cognitive outcomes. Unfortunately, it only does this in passing, and hints at some powerful uses for instructional audio for learning conceptual content (e.g. including environmental sounds, drama, etc.)

Not only does this brief article provide helpful guidelines for selecting the audio medium for instruction (viz. the five bullet points above), it has piqued my curiosity regarding podcasts that aim for outcomes in the affective domain. I plan to review directories of educational podcasts and see if I can determine the ratio of procedural/cognitive podcasts to conceptual/affective podcasts.